v0.8.4, build 167

Added the possibility to provide default options for the icon finder assistant
Added the possibility to provide default options for the translation assistant
Added the possibility to provide default options for the coding assistant
Added the possibility to provide default options for the text summarizer assistant
Improved readability of the issue component
Improved switches: when an option is enabled, the switch is using a different color
Fixed the applying of spellchecking settings to the single-line dialog
Restructured the layout of the settings page
Refactored the settings data model
Upgraded to Rust 1.80.0
Upgraded all Rust dependencies